Vitamin D 3 synthetic studies. Intramolecular Diels-Alder approaches to the CD-ring fragment
作者:Martin C. Clasby、Donald Craig、Albert A. Jaxa-Chamiec、Justine Y.Q. Lai、Andrew Marsh、Alexandra M.Z. Slawin、Andrew J.P. White、David J. Williams
DOI:10.1016/0040-4020(96)00147-0
日期:1996.3
The enantiospecific synthesis of the vitamin D3 CD ring fragment 3 is reported. Key steps are the diastereoselective allylation of a norephedrine/dihydrocitronellic acid-derived oxazolidinone, and the intramolecular Diels-Alder reaction of a sulfonyl-substituted dienyne. The analogous cycloaddition reaction of a trienylsulfone substrate is shown to give products having the incorrect stereochemistry
据报道维生素D 3 CD环片段3的对映体特异性合成。关键步骤是降麻黄碱/二氢香柠檬酸衍生的恶唑烷酮的非对映选择性烯丙基化,以及磺酰基取代的二烯炔的分子内Diels-Alder反应。三烯砜底物的类似环加成反应显示出具有不正确的立体化学的维生素D 3合成产物。